Don't be a tool and hint on the radio with ATC instead of making an out right request for what you want because you 'expect' it. Like saying "cathay XXX reaching FL200" when you don't want to level off on the way to higher altitude instead of just saying "cathay XXX request higher" the first is a hint as if they forgot about you and not paying attention, the second is a direct request implying anything further. The first will get your head bitten off, and the second will tell you the reason why you're being leveled there which is either traffic or sector hand off snag.
Well if you had some situational awareness maybe you would realise there is oncoming traffic and not ask for a climb, you could also possibly say level so to notify ATC that he/she has nothing to worry about.
